The solution to the southern Democrats’ abuses of power was the Voting Rights Act of 1965. It was enacted after litigation on a case-by-case basis proved insufficient to curtail Fifteenth Amendment violations: State legislatures became adept at replacing unconstitutional laws with new ones that had a similar effect. In response, the 1965 act prohibited states from adopting practices or procedures that deny or abridge Americans’ right to vote. Crucially, the authors of the act recognized that obstructionist states could be singled out for extra scrutiny. Politicians in those states were prohibited from making arbitrary changes to voting rules.
The same approach can remedy abuses by anti-gun states. The Second Amendment applies to the states via the Fourteenth Amendment, which allows Congress to police the actions of wayward states “by appropriate legislation.” It’s true that Congress is limited to remedying or preventing unconstitutional actions, as the Supreme Court stressed in a 1997 religious-freedom case. But even in that case, a majority of the justices said Congress “must have wide latitude” in enacting laws to protect constitutional rights “despite the burdens those measures placed on the States.”